A growing movement of conservationists proposes to stem biodiversity losses by setting aside half of Earth’s land as an interconnected global conservation reserve. As the largest land governance proposal in history, Half Earth engages with some of the wickedest challenges in land system science. How best to allocate and manage Earth’s land to maximize biodiversity conservation in the face of competing demands for food, housing and other human needs? Can half of Earth’s land be reallocated and governed fairly and equitably in ways that honor the rights of vulnerable populations? Who will pay for and govern this project? Half Earth’s prosocial aspirational vision could help to inspire and sustain the global, regional and local efforts needed to conserve biodiversity across the Anthropocene. It is time for a broader discussion of the social-ecological opportunities, trade-offs, and challenges that a global conservation reserve project at the scale of Half Earth would create. In so doing, we must begin by recognizing the central role of social processes, institutions, and strategies in making such efforts possible, with a focus on adaptive multi-level systems of landscape governance that benefit people as much as they benefit the natural world.

越来越多的环境保护主义者提出，通过预留地球一半的土地作为相互联系的全球保护区，来阻止生物多样性的丧失。作为有史以来最大的土地治理提案，《半个地球》面临着土地系统科学中最邪恶的挑战。面对对食物，住房和其他人类需求的竞争需求，如何最好地分配和管理地球的土地，以最大程度地保护生物多样性？能否以尊重弱势群体权利的方式公平，公正地重新分配和管理地球一半的土地？谁来支付和管理该项目？半地球的亲社会理想愿景可以帮助激发和维持为人类世界保存生物多样性所需的全球，区域和地方努力。现在是时候就一个半地球规模的全球自然保护区项目将产生的社会生态机会，权衡和挑战进行更广泛的讨论了。在这样做时，我们必须首先认识到社会过程，机构和策略在使这种努力成为可能的过程中所起的核心作用，并着重于适应性多级景观管理系统，这种系统既使人们受益，又使他们受益于自然世界。